The climbing capabilities of living creatures such as geckos, tree frogs, and inchworms provide a promising platform for exploiting biomimetic soft climbing robots. However, achieving this promise remains a grand challenge in materials science and engineering.
Now, inspired by the incredible gripping ability of geckos and the efficient locomotion of inchworms, engineers at the University of Waterloo have developed a tiny robot that could one day help doctors perform surgery.
The new robot – dubbed the GeiwBot by researchers – utilizes ultraviolet (UV) light and magnetic force to move on any surface, even up walls and across ceilings. It is the first-of-its-kind soft robot that doesn’t require connection to an external power supply, enabling remote operation and versatility for potential applications such as assisting surgeons and searching otherwise inaccessible places.
“This work is the first time a holistic soft robot has climbed on inverted surfaces, advancing state-of-the-art soft robotics innovation,” said Dr. Boxin Zhao, a professor of chemical engineering. “We are optimistic about its potential, with much more development, in several different fields.”
The robot is about four centimeters long, three millimeters wide, and one millimeter thick. It is constructed from a smart material that can be altered at the molecular level to mimic how geckos stick and unstick powerful grippers on their feet. This enables the robot to climb on a vertical wall and across the ceiling without being tethered to a power source.
Zhao and his team build GeiwBot using liquid crystal elastomers and synthetic adhesive pads. A light-responsive polymer strip simulates the arching and stretching motion of an inchworm, while gecko-inspired magnet pads at either end do the gripping.
“Even though there are still limitations to overcome, this development represents a significant milestone for utilizing biomimicry and smart materials for soft robots,” said Zhao, the University of Waterloo Endowed Chair in Nanotechnology. “Nature is a great source of inspiration, and nanotechnology is an exciting way to apply its lessons.”
An untethered soft robot opens a door for potential surgical applications via remote operation inside the human body and for sensing or searching in dangerous or hard-to-reach places during rescue operations.
In the next step, researchers plan to develop a solely light-driven climbing soft robot that doesn’t require a magnetic field and uses near-infrared radiation instead of UV light to improve biocompatibility.
- Jian Sun, Lukas Bauman, Li Yu, and Boxin Zhao. Gecko-and-inchworm-inspired untethered soft robot for climbing on walls and ceilings. Cell Reports Physical Science, 2023; DOI: 10.1016/j.xcrp.2022.101241